Tamper proof closure for containers of liquids

ABSTRACT

A tamper-proof closure element made of plastic material for containers ( 1 ) of drinks comprises a main body ( 2 ) with circular-cylindrical shape, circular-cone frustum shape, defined by an upper surface ( 3 ) and a lower annular coating ( 4 ) in a single body to enclose an end portion of the container ( 1 ), and a lateral portion provided with a pair of weakening and/or breakage lines ( 9   a   , 9   b ) extending from the free edge ( 4   a ) of the annular coating ( 4 ) for a length of a value (C); this pair of lines ( 9   a   , 9   b ) are mutually separated, in correspondence with their final segment situated far from the free edge ( 4   a ), by a value (A) and, in correspondence with the free edge ( 4   a ), by a value (B); these three values (A, B, C) are mutually computed at least as a function of the diameters (D, D 1 ) and of the height (H) of the neck ( 6 ) of the container ( 1 ) and of the pressure present or able to be generated inside the container ( 1 ), in such a way as to allow, subsequently to the initial opening separation, through related manual grip means ( 10 ), of the main body ( 2 ) from the neck ( 6 ) and causing a partial or total breakage of the weakening and/or breakage lines ( 9   a   , 9   b ), the re-closure of the container ( 1 ) with the compensation of the pressure of the pressure present or able to be generated within the container itself ( 1 ).

TECHNICAL FIELD

[0001] The present invention relates to a tamper-proof closure element made of plastic material for containers of liquids, in particular for drinks.

BACKGROUND ART

[0002] Currently in the technical field pertaining to container closure systems, i.e. the so-called “closing caps” for bottles made of plastic and glass, there is an ever greater need to find effective alternatives to the traditional metal crown closures or to the caps made of plastic material applicable by means of screwing.

[0003] This need for effective alternatives to traditional caps is more deeply felt in the case of containers for drinks, such as beers or last-generation soft drinks, which, usually, must or need to be re-closed after the initial opening because they have not been fully emptied and also provide for the possibility of releasing any overpressure gases which are created when the container is handled (this feature is known in the sector as “venting”); in addition, the caps used must provide the classic characteristics (in particular those made of plastic material) of verification of first-opening integrity (known as “tamper evidence” or “tampering proof”) and not to have a negative impact on the structure of the neck of the container to allow the reuse of the container itself.

[0004] Currently, these containers-bottles, in particular the plastic ones, are closed according to three types of caps: the first one is represented by the classic screw cap (either made of a metallic material, generically aluminium, or of plastic material, generically polyolefin based, such as polyethylene or polypropylene) which, clearly, allows to re-close the container after the initial opening, and to vent outside the container (at each subsequent opening) the gases created by the drink if the container is moved, but has the drawback of a high cost in itself, in addition to requiring necessarily the presence, on the neck of the container, of threads for screwing.

[0005] The second solution is represented by a metal cap (usually made of aluminium) whereto is associated a ring for the opening grip wound or set close to the neck of the container; this cap needs a low application force for opening the container, does not scratch the closure area of the bottle neck and, therefore, can be applied on reusable bottles. The drawbacks of such a cap, on the other hand, are its high cost of manufacture, the impossibility of closing the container again after the initial opening, and low usage safety, since the user can risk, if he/she does not perform the opening manoeuvre correctly, to injure him/herself due to the presence of extremely sharp and cutting surfaces; additionally, it requires the use of both hands.

[0006] The third solution present on the market is given by the traditional crown cap which represents the most widely used cap on the market because of its characteristics of seal security, low cost both in terms of production plant and of the product itself.

[0007] The drawbacks of the crown cap, in the specific case, are given: by the high axial loads on the bottle of the container when the closure is mounted, with consequent difficulties (or impossibility) of application on containers constituted by plastic material for the risk of destruction of the container itself during the capping process; by the impossibility, or difficulty, of opening the container manually; by the impossibility of a correct subsequent closure of the container because of the irreversible deformation of the cap, once opened, and, lastly, by the impossibility of a subsequent reuse of the container—if made of plastic material—because the corrugations and the tightening force of the closure irremediably scratch the mouth of the container.

DISCLOSURE OF INVENTION

[0008] The aim of the present invention, therefore, is to eliminate the aforesaid drawbacks by providing a closure element for containers of drinks that is extremely simple in its manufacturing configuration, has low cost of production, and is structured in such a way as to provide a series of technical-practical characteristics that meet the demands of the market, i.e.: use of containers-bottles also made of plastic material with the need for their reuse, i.e. “refillable”; allow for an easy application on the container also and, possibly, by means of the same closure plants, to apply crown cap types of closures, used to date on bottling lines; a facilitated opening operation also with the use of only one hand; the possibility to indicate unequivocally the opening of the container, the possibility of re-closing the container after the first opening with the automatic adjustment of the value of the pressure within it due to the artificial gassing of the drinks, or, possibly, to their natural fermentation.

[0009] The aforesaid aims are achieved by means of a closure element made of plastic material for containers of drinks comprising a main body with circular-cylindrical shape defined by an upper surface and a lower annular coating in a single body to enclose an end portion of the container, and a lateral portion provided with a pair of weakening and/or breakage lines extending from the free edge of the annular coating for a length of a first value; this pair of lines are mutually separated, in correspondence with their final segment situated far from the free edge, by a second value and, in correspondence with the free edge, by a third value; these three values are mutually calculated at least as a function of the inner and outer diameter of the neck of the container and of the pressure present or able to be generated inside the container, in order to allow, subsequently to the initial opening separation, by means of related manual grip means, of the main body from the neck and causing a partial or total breakage of the weakening and/or breakage lines, the re-closure of the container with the compensation of the pressure present or able to be generated inside the container itself

DESCRIPTION OF THE DRAWINGS

[0010] The technical features of the invention, according to the aforesaid aims, can clearly be noted from the content of the claims set out below and its advantages shall become more readily apparent in the detailed description that follows, made with reference to the accompanying drawings, which represent an embodiment provided purely by way of non limiting example, in which:

[0011]FIG. 1 shows a first constructive diagram of a closure element for containers of liquids, according to the present invention, in a schematic perspective view;

[0012]FIG. 2 shows a container for drinks provided with a first embodiment of the closure element of the present invention, in a schematic front view;

[0013]FIG. 3 shows a detail in enlarged scale of the container of FIG. 2 in a schematic front view;

[0014]FIG. 4 shows the closure element of FIGS. 2 and 3 in a partially sectioned lateral view, shown in enlarged scale relative to FIGS. 2 and 3;

[0015]FIGS. 5, 6 and 7 show the closure element of FIGS. 2, 3 and 4 in corresponding three opening phases of the container, all in schematic lateral views with some parts sectioned;

[0016]FIG. 8 shows a second constructive diagram of a closure element for containers of liquids, according to the present invention, in a schematic perspective view;

[0017]FIGS. 9 and 10 show the closure element obtained according to the diagram of FIG. 8, respectively in positions of closure and subsequent opening of the container and in schematic perspective views;

[0018]FIGS. 11, 12, 13 and 14 show the closure element of FIGS. 9 and lo in a corresponding series of phases for the opening of the container by means of lifting the element, and all figures are schematic lateral views with some parts sectioned;

[0019]FIGS. 15, 16, 17, 18, 19 and 20 show the closure element of FIGS. 9 and 10 in a corresponding series of phases for the opening of the container by means of pressure on the closure element, and all figures are schematic lateral views with some parts sectioned;

[0020]FIG. 21 shows a third embodiment of the subject closure element in a schematic lateral view;

[0021]FIG. 22 shows a detail referred to FIG. 21 in a schematic front view;

[0022]FIGS. 23 and 24 show a system for applying the closure element of FIGS. 1 through 22 in a detail shown in lateral view with some parts sectioned and illustrating an application terminal encompassing the closure element

DESCRIPTION OF THE ILLUSTRATIVE EMBODIMENTS

[0023] In accordance with the figures of the accompanying drawings, and with particular reference to FIGS. 1 and 2, the subject closure element, made of plastic material, is applied onto containers 1 of drinks, such as beer, tea, soft drinks in general or similar drinks, without thereby limiting the inventive scope of the subject invention.

[0024] The plastic material for the manufacture of this closure element can be of various types (without thereby limiting others), such as polyethylene terephtalate or polyethylene naphtalenate.

[0025] This closure element comprises a main body 2, with circular-cylindrical shape (or more specifically circular-cone shape), defined by an upper surface 3 and a lower annular coating 4 in a single body to enclose an end portion of the aforesaid container 1 comprising a mouth 5 for the exit of the drink defined by the mouth 6 of the container 1.

[0026] The aforesaid annular coating 4, moreover, has, along its own inner surface, an annular tooth 7, defining an undercut for the stable coupling with a corresponding annular rib 8 presented by the neck 6 of the container 1.

[0027] As FIGS. 1 and 8 clearly show, the closure element of this type also comprises a lateral portion provided with a pair of weakening and/or breakage lines 9 a and 9 b, which interrupt the aforesaid tooth 7, extending from the free edge 4 a of the aforesaid annular coating 4 for a length of a first value, indicated with the reference C.

[0028] In addition, the pair of weakening and/or breakage lines 9 a and 9 b are mutually separated, in correspondence with their final segment situated far from the free edge 4 a, by a second value, indicated with the reference A, and, in correspondence with the free edge 4 a, by a third value, indicated as B.

[0029] These three values A, B and C are mutually calculated at least as a function of the (inner and outer) diameters D and D1 and of the height H of the neck 6 of the container 1 and of the pressure present or able to be generated inside the container 1: it is thereby possible to obtain, subsequently to the initial opening separation of the closure element from the neck 6—performed through related manual grip means 10 associated with the annular coating 4—and causing a partial or total breakage of the weakening and/or breakage lines 9 a and 9 b, the re-closure of the container 1 with compensation of the pressure present or able to be generated inside the container itself.

[0030] More specifically, in the case shown in FIGS. 1 and 8, the aforesaid pair of weakening and/or breakage lines 9 a and 9 b are obtained on the annular coating 4 to form a substantially trapezoidal configuration.

[0031] If we observe only the geometric shape of the solution shown in FIG. 1, the pair of lines 9 a and 9 b present the aforesaid value A greater than value B, whilst value C is greater than value B. but smaller than A: these dimensions are, as previously mentioned, a function of the diameters D and D1 and of the height H of the neck 6 of the container 1 and/or of the pressure able to be generated by the product contained therein after the opening of the container 1 itself.

[0032] Observing FIG. 1, one can not that each weakening and/or breakage line 9 a and 9 b comprises a first rectilinear segment S1 and a second segment S2 inclined relative to the first, joined together without interruptions.

[0033] More specifically, each rectilinear first segment S1 is obtained in proximity to the free edge 4 a, and the second segment S2 is inclined away from the corresponding second segment of the other weakening and/or breakage line to define a diverging angle shape with maximum distance away in correspondence with the segment farthest from the free edge 4 a.

[0034]FIGS. 2 and 3 clearly show the aforementioned manual grip means 10, which, in this first embodiment, comprise an extension 11 of the annular coating 4, located between the pair of weakening and/or breakage lines 9 a and 9 b. This extension 11, in,the illustrated case with ellipsoidal shape, develops beyond the free edge 4 a in such a way as to allow, in correspondence with its lifting with movement away from the neck 6 of the container 1 (see arrow F6 of FIG. 6), an opening of the same container 1 with breakage of the aforementioned weakening and/or breakage lines 9 a and 9 b.

[0035] To obtain a correct opening operation of the container 1, the main body 2 is provided with a first weakening (see FIG. 4) achieved by a first undercut 12 obtained on the outer surface of the main body 2 in correspondence with the junction area between the upper surface 3 and the aforesaid annular coating 4 in such a way as to define a hinge point able to facilitate the opening operation of the container 1, increasing the elastic flexibility of the area of the annular coating 4.

[0036]FIG. 4 shows a second weakening, also achieved by a second undercut 13 obtained, however, on the inner surface of the main body 2, in contact with the aforesaid neck 6 of the container 1, and in correspondence with the junction area between the upper surface 3 and the annular coating 4 in such a way as to define an additional second hinge point able further to increase the elastic flexibility of the closure element during the opening phase, without thereby generating irreversible fractures on the main body 2 or on the annular coating 4. The two hinge points 12 and 13 described above can be obtained individually or as a pair.

[0037] The individual or simultaneous presence of the hinge undercuts 12 and 13 is a function at least of the elastic characteristics of the plastic material used to manufacture the closure elements and of the dimensions of the neck 6 of the container 1.

[0038] Both these first and second undercuts 12 and 13, if present, are preferably obtained in the area of the main body 2 lying between the pair of weakening and/or breakage lines 9 a and 9 b to allow a more direct action on the area wherein the extension 11 acts.

[0039] To confirm the validity of the embodiment described above, in a second embodiment, illustrated starting from FIG. 8, the geometric configuration defined by the weakening lines 9 a and 9 b forms a classic trapezoid wherein the value A is smaller than the value B, whilst the value C is smaller both than the value A and of the value B.

[0040] As clearly shown also in FIGS. 9 and 10, the aforesaid opening means 10 S also comprise an extension 14 of the annular coating 4 beyond the free edge 4 a, lying between the pair of weakening and/or breakage lines 9 a and 9 b.

[0041] This extension 14 is provided (see also FIGS. 11 through 20), with a pair of hinge points 15 and 16, distanced between them, and with cam means 17, defined by the inner profile of the extension 14, in contact and acting with the neck 6 of the container 1.

[0042] This structure of the extension 14 allows, indifferently, the opening of the container 1 by lifting the extension 14 itself away from the neck 6, or by thrusting the same extension 14 against the neck 6 of the container 1.

[0043] More in detail, the first hinge point 15 is defined by a first undercut 18 obtained on the outer surface of the main body 2 in correspondence with the junction area between the upper surface 3 and the annular coating 4; this first undercut 18 is also obtained in the area lying between the two lines 9 a and 9 b.

[0044] The second hinge point 16 is obtained from the partial separation of the extension 14 of the annular coating 4 in the area proximate to the free edge 4 a, in addition to the aforesaid annular tooth 7 holding the main body 2 on the neck 6: this configuration allows to define a single manually operated lever.

[0045] This individual lever 14 is provided by a substantially concave inner profile 19, defining the aforesaid cam means 17, and able to allow, in correspondence with a pressure on the lever 14 (see arrow F14 of FIGS. 18 and 19), a rotation of the lever itself towards the neck 6 with related thrust both on the free edge 4 a, and on the portion of the annular tooth 7 lying between the weakening and/or breakage lines 9 a and 9 b, from the interior, in such a way as to allow a movement of the free edge 4 a away from the neck 6 with related opening of the container 1 (see arrow F4 of FIGS. 19 and 20).

[0046] Again to confirm the extreme validity of the aforementioned embodiments, FIG. 21 shows an additional accessory embodiment for this closure element.

[0047] In the case shown, the closure element comprises means 20 for holding the main closure body 2 on the neck 6 of the container 1. These means 20 are positioned in proximity to the neck 6 and allow the main body 2 to remain secured to the container 1 even after the opening of the container 1 obtained with the aforesaid opening means 10.

[0048] Purely by way of example, these holding means 20 can comprise a holding ring 21 positioned below the main closure body 2; the ring 21 is provided with a plurality ofjunctions 22 and 23 joining with the free edge 4 a of the main body 2 (the number is a function of the diameter of the main body and two are visible herein by way of example) and with a hinge point 24 obtained diametrically opposite the area presenting the aforesaid opening means 10: this structuring of these means 20 allows, in correspondence with the opening phase, a breakage of the junctions 22 and 23 present and a rotation of the main body 2 about the hinge point 24 (see arrow F24 of FIG. 21) with related holding of the main body 2 on the neck 6 of the container 1.

[0049]FIG. 22, purely by way of example, illustrates the aforesaid hinge point 24, which can comprise at least a folding tab associated with the free edge 4 a and with the holding ring 21. Additionally, bilateral bulges 25 can be added, also associated to the free edge 4 a and to the ring 21 and able to serve as further hinge constraints for a correct rotation of the main body 2 during the opening and re-closing operations.

[0050] A closure element thus obtained fully achieves the pre-set aims and can be used in the ways shown in FIGS. 5 through 7 for the first embodiment, and in FIGS. 11 through 20 for the second embodiment.

[0051]FIGS. 5 through 7 clearly show the opening phase of the container 1 by means of lifting the extension 11 (see arrow F6) which, helped by the presence of one or both the undercuts 12 and 13 for its rotation, determines the fracture of the lines 9 a and 9 b, with the consequent move away of the tooth 7 lying between the weakening and/or breakage lines 9 a and 9 b from the annular rib 8 opening, in fact, the container 1.

[0052] Similarly in FIGS. 11 through 14, the lever 14 of this embodiment can be lifted (see arrow F16 of FIGS. 12 and 13) rotating about the second hinge point 16 with consequent thrust on the free edge 4 a and distancing of the portion of the tooth 7 lying between the lines 9 a and 9 b for weakening and/or breaking the annular rib 8) also aided by the first hinge point 15 and by the breakage of the weakening lines 9 a and 9 b ). After obtaining the distancing between the portion of the tooth 7 lying between the weakening and/or breakage lines 9 a and 9 b and the rib 8, it is possible to thrust the main body 2 upward (see arrow F15 of FIG. 14) to obtain the opening of the container 1.

[0053] The constructive architecture of this closure element allows, as mentioned above, to perform the opening operation by pressing on the lever 14.

[0054] By pressing on the lever 14 (see arrow F14 of FIGS. 16 and 17), one obtains a rotation of the same lever in the direction of the neck 6 (thanks to the second hinge point 16) with related trust both on the free edge 4 a, and on the portion of the annular tooth 7 lying between the weakening and/or breakage line 9 a and 9 b, from the interior of the main body 2 and thanks to the particular shape of the inner profile of the lever 14 and to the help provided by the breakage of the lines 9 a and 9 b.

[0055] This thrust imparted by the lever 14 allows the movement of the free edge 4 a away from the neck 6 with the release of the tooth portion 7 from the rib 8 with the related opening of the container 1 (see arrow F4 of FIGS. 19 and 20).

[0056] As FIGS. 23 and 24 show, the closure element described above can easily be applied to the containers 1 through extremely limited technical variations on existing capping lines (in particular, on those for crown caps). Capping lines can simply be provided, purely by way of non limiting example of the solution, with a terminal 26 applicable under the capping head of the lines conveying the containers 1. This particular terminal 26 can simply be shaped in such away as to encompass the closure element on the upper part thereof involving also the portions comprising the weakening and breakage line; in this way the capping operation will be simple and will not compromise the integrity of the closure itself.

[0057] This closure element made of plastic material therefore achieves all pre-set aims thanks to a global structure that is extremely rational and has application and functionality characteristics that are sharply superior to the solutions presented to date by the market.

[0058] The use of a configuration of the main body provided with a pair of weakening and/or breakage lines which, in practice, determine an interruption on the surface of the main body with possibility to control the circling power of the tooth on the rib, control effected by computing the dimensions of the aforesaid values A, B, C, has allowed to meet a plurality of technical specifications on this single closure element, such as:

[0059] ease of opening of the container also with one hand only and according to different possibilities, i.e. lifting or pressure on the extension thanks to the low force required for opening;

[0060] possibility to verify, visually, the integrity of the container thanks to the weakening and/or breakage lines;

[0061] possibility to re-close the container after the first opening thanks to the weakening lines which, through their configuration and their dimensioning on the body allow an automatic adjustment of the value of the pressure inside the container for drinks gassed both artificially, and by natural fermentation;

[0062] possibility to reuse the container thanks to the particular structure of the opening means which do not incise the neck area covered by the closure element;

[0063] possibility for nearly complete reuse of existing bottling lines for the application of crown caps with the simple adaptation of the head for applying the closure elements.

[0064] The invention thus conceived can be subject to numerous modifications and variations, without thereby departing from the scope of the inventive concept. Moreover, all components can be replaced by technically equivalent elements. 

1. A tamper-proof closure element made of plastic material for containers (1) of drinks comprises a main body (2) with circular-cylindrical shape, i.e. circular-cone frustum shape, defined by an upper surface (3) and a l (4) in a single body to enclose an end portion of the container (1), comprising a mouth (5) for the outflow of said drink and defined by the neck (6) of said container (1); said annular coating (4) presenting, along its own inner surface, a tooth (7) defining an undercut for the stable coupling with a corresponding annular rib (8) presented by said neck (6) of the container (1), said closure element being characterised in that it comprises a lateral portion provided with a pair of weakening and/or breakage lines (9 a, 9 b ) extending from the free edge (4 a ) of said annular coating (4) for a length of a value (C); said pair of weakening and/or breakage lines (9 a, 9 b ) being mutually separated, in correspondence with their final segment situated far from the free edge (4 a ), by a value (A) and, in correspondence with the free edge (4 a ), by a value (B); said three values (A, B, C) being mutually computed at least as a function of the diameters A), D1) and of the height (H) of the neck (6) of said container (1) and of the pressure present or able to be generated inside the container (1), in such a way as to allow, subsequently to the initial opening separation, through manual grip means (10) associated with said annular coating (4), of said closure element from said neck (6) and causing a partial or total breakage of the weakening and/or breakage lines (9 a, 9 b ), the re-closure of said container (1) with the compensation of the pressure present or able to be generated within the container itself.
 2. A closure element as claimed in claim 1, characterised in that said pair of weakening and/or breakage lines (9 a, 9 b ) are obtained on said annular coating (4) to form a substantially trapezoid configuration.
 3. A closure element as claimed in claim 1, characterised in that said value (A) is greater than said value (B).
 4. A closure element as claimed in claim 1, characterised in that said value (A) is smaller than said value (B).
 5. A closure element as claimed in claims 1 to 3, characterised in that each said weakening and/or breakage line (9 a, 9 b ) is composed by a first rectilinear segment (S1) and a second segment (S2) inclined relative to the first and joined together without any interruptions.
 6. A closure element as claimed in claim 5, characterised in that each said first rectilinear segment (S1) is obtained in proximity to the free edge (4 a ) and the second segment (S2) is inclined away from the corresponding second segment (S2) of the other said weakening and/or breakage line (9 a, 9 b ) to define a diverging angle profile with maximum distancing in correspondence with said farther away segment from said free edge (4 a ).
 7. A closure element as claimed in claims 1 through 3, characterised in that said value (C) is greater than said value (B).
 8. A closure element as claimed in claims 1 through 3 and from 5 to 6, characterised in that said value (A) is greater than said value (C).
 9. A closure element as claimed in claims 1 through 3, characterised in that said manual grip means (10) comprise and extension (11) of said annular coating (4) beyond said free edge (4 a ), lying between said pair of weakening and/or breakage lines (9 a, 9 b ), able to allow, in correspondence with its lifting away from said neck (6) of the container (1), an opening of the container (1) with the breakage of said weakening and/or breakage lines (9 a, 9 b ).
 10. A closure element as claimed in claim 9, characterised in that it comprises a first weakening obtained from a first undercut (12) obtained on the outer surface of said main body (2) in correspondence with the junction area between said upper surface (3) and said annular coating (4) in such a way as to define a hinge point able to facilitate the opening operation of said container (1).
 11. A closure element as claimed in claim 9, characterised in that it comprises a second weakening obtained from a second undercut (13) obtained on the inner surface of said main body (2), in contact with said neck (6) of the container (1), in correspondence with the junction area between said upper surface (3) and said annular coating (4) in such a way as to define a second hinge point able to facilitate the opening operation of said container (1).
 12. A closure element as claimed in claim 9, characterised in that it comprises a first and a second weakening achieved by a related first and second undercut (12, 13) obtained, respectively, the first, on the outer surface of said main body (2) in correspondence with the junction area between said upper surface (3) and said annular coating (4), and the second on the inner surface of said main body (2), in contact with said neck (6) of the container (1), in correspondence with the junction area between said upper surface (3) and said annular coating (4) in such a way as to define related first and second hinge points able to facilitate the opening operation of said container (1).
 13. A closure element as claimed in claims 9 through 12, characterised in that said first and second undercut (12, 13) are obtained in the area of said main body (2) lying between said pair of weakening and/or breakage lines (9 a, 9 b ).
 14. A closure element as claimed in claims 1, 2 and 4, characterised in that said opening means (10) comprise an extension (14) of said annular coating (4) beyond said free edge (4 a ) and lying between said pair of weakening and/or breakage lines (9 a, 9 b ); said extension (14) being provided with at least a pair of hinge points (15, 16), distanced from each other, and with cam means (17), defined by the inner profile of said extension (14), in contact and acting with said neck (6) of the container (1) able to allow said opening of the container (1), by lifting said extension (14) away from said neck (6), or pressing on the same extension (14) against said neck (6) of the container (1).
 15. A closure element as claimed in claim 14, characterised in that said first hinge point (15) is defined by a first undercut (18) obtained on the outer surface of said main body (2) in correspondence with the junction area between said upper surface (3) and said annular coating (4).
 16. A closure element as claimed in claims 14 and 15, characterised in that said second hinge point (16) is obtained by the partial separation of said extension (14) from said annular coating (4) in the area proximate to said free edge (4), beyond an annular tooth (7) for holding said main body (2) on said neck (6), and in such a way as to define a single manually operated lever.
 17. A closure element as claimed in claims 14 through 16, characterised in that said single lever (14) is provided with a substantially concave inner profile (19), defining said cam means (17), and able to allow, in correspondence with a pressure on said lever (14), a rotation of the lever towards said neck (6) with related thrust both on said free edge (4 a ), and on the portion of said annular tooth (7) lying between said weakening and/or breakage lines (9 a, 9 b ), from the interior, in such a way as to allow a movement away of the free edge (4 a ) itself from said neck (6) with related opening of said container (1).
 18. A closure element as claimed in claim 1, characterised in that it comprises means (20) for holding said main closure body (1), situated in proximity with said neck (6), and able to allow to maintain the main body (2) itself secured to said container (1) also subsequently to said opening phase of the container (1) obtained through said opening means (10).
 19. A closure element as claimed in claim 18, characterised in that said holding means (20) comprise a holding ring (21) positioned below said main closure body (2), and provided with at least a pair ofjunctions 22, 23 joining with the free edge (4 a ) of said main body (2) and a hinge point (24) obtained diametrically opposite from the area presenting said opening means (10) in such a way as to allow, in correspondence with said opening phase, a breakage of said junctions (22, 23) and a rotation of said main body (2) about said hinge point (24).
 20. A closure element as claimed in claim 19, characterised in that said hinge point (24) comprises at least a folding tab associated to said free edge (4 a ) and to said holding ring (21). 